Differential gear system using the change in input direction to control the output speed ratio

ABSTRACT

A differential motion gear system that controls the output speed ratio by changing the revolving direction of the input shaft. Different embodiments produce different combinations of output direction and output speed ratio.

SUMMARY OF THE INVENTION

The present invention refers to a differential motion gear system tocontrol the speed ratio by means of the change of input direction. Itcauses the changing of the output speed ratio by changing the revolvingdirection of the input shaft of the differential motion gear system.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is the schematic drawing of the fundamental principle of thedifferential motion gear system to control the speed ratio by means ofchanging the input direction.

FIG. 2 is the schematic drawing of the embodiment of the differentialmotion gear system according to the invention to control the speed ratioby means of changing the input direction by using an external gear withthe input shaft.

FIG. 3 is the schematic drawing of the application of the differentialmotion gear system according to the invention to control the speed ratioby means of changing the input direction by using a driving arm of thedifferential gear to drive the input shaft directly.

FIG. 4 is the schematic drawing of the application of the differentialmotion gear system according to the invention to control the speed ratioby changing the input direction in combination with an external gearwith the input shaft.

FIG. 5 is the schematic drawing of an embodiment with a series typequick-return differential motion gear system to control the speed ratioby means of changing the input direction.

FIG. 6 is the schematic drawing of an embodiment with a parallel typequick-return differential motion gear system to control the speed ratioby means of changing the input direction.

FIG. 7 is the schematic drawing of an embodiment with a double-actingtype quick-return differential motion gear system to control the speedratio by means of changing the input direction.

DETAILED DESCRIPTION OF THE INVENTION

The present invention refers to a differential motion gear system tocontrol the speed ratio by means of changing the input direction. Itcauses the conversion of the output speed ratio by changing therevolving direction of the input shaft of the differential motion gearsystem.

FIG. 1 is the schematic drawing of the fundamental principle of thedifferential motion gear system to control the speed ratio by means ofchanging the input direction comprising:

an input sun gear T1 coupled with a differential motion gear T3 andcombined with input axis or shaft SO;

the differential motion gear T3 is constituted by one or more sets ofplanet gears, and is coupled between the sun gear T1 and ring gear T2.The driving arm A3 drives the differential motion gear driven outputshaft S1 via the one-way driving mechanism SC31 and is coupled with thestationary case via reverse one-way driving mechanism SC32;

the ring gear T2 is coupled with the differential motion gear T3; withthe output shaft S1 via a one-way driving mechanism SC21; and with thestationary case via reverse one-way driving mechanism SC22;

the above one-way driving mechanisms SC21 and SC31 allow coupling withthe output shaft S1 in parallel in the same direction, or with theoutput shaft S1 coaxially as an internal gear and an external gear. Theone-way driving mechanisms SC22 and SC32 installed between the rockerarms of the ring gear and the differential motion gear and thestationary case operated in same direction and against the direction ofthe above mechanisms SC31 and SC32. They allow installation in parallelto or coaxially between the stationary case and the rocker arms to bedriven by the ring gear and the differential gear.

Based on the above structure, taking the example of the selective designof that in the one-way driving mechanism of the ring gear, thedifferential motion gear and the stationary case, the former idlesclockwise, and it is able to drive clockwise by coupling with the outputshaft S1. The differential motion system to control the speed ratio bychanging the input direction may take the form of one of the followingtwo kinds of output:

A. While the input shaft SO revolves clockwise (CW), counterclockwisetorsion of the external gear is restricted by the one-way drivingmechanism SC22, the driving arm A3 of the differential motion gear T3drives the output shaft S1 clockwise via one-way driving mechanism SC31and the speed ratio is:

    R=1+T2/T1

B. While the input axis SO revolves counterclockwise (CCW), on accountof the counterclockwise torsion of the driving rocker arm A3 of thedifferential motion gear T3 is restricted by the one-way drivingmechanism SC32. The ring gear T2 drives the output shaft S1 clockwisevia the one-way driving mechanism SC21 and the speed ratio is:

    R=-T2/T1

Based on the above fundamental principle, there are multiple practicalembodiments including the use of the sun gear, the differential motiongear or the ring gear as the input. The other two gears of the abovethree gears will be coupled between the output shaft and the stationarycase via the one-way driving mechanism based on the above-principle. Forexample:

As shown in FIG. 2, the embodiment using the ring gear as the input hasthe relationships as follows:

The ring gear T2 is connected with the input source to provide theinput;

The sun gear T1 and the differential motion gear T3 mutually drive andare coupled with the output shaft S1 via the one-way driving mechanismSC131.

The driving rocker arm A3 of the differential motion gear T3 is coupledso as to rotate with the output shaft S1. A one-way driving mechanismSC122 is installed between the rocker arm A3 and the fixed case, and theacting direction is the same as that of the one-way driving mechanismSC131 of the sun gear T1 coupled with the output shaft.

The relationship of output is that on the first rotating direction, thearm A3 to be driven by the differential motion gear T3 is madestationary by the one-way driving mechanism SC122 between thedifferential motion gear T3 and the stationary case. The output shaft S1is driven by the sun gear T1 via the one-way driving mechanism SC131.The output ratio will be:

    R=-T1/T2

When the input shaft SO rotates reversely, the sun gear T1 is restrictedby the one-way driving mechanism SC131 between itself and the fixedcase. This time the output shaft S1 is driven by the driving arm A3 ofthe differential gear T3, and the output ratio will be:

    R=1+T1/T2

Owing the reversal of the driving direction, the output will always beon the same direction in both input directions of the driving gear.

FIG. 3 shows an example wherein the driving arm A3 of the differentialmotion gear T3 is driven by the input directly. The relationships willbe:

The driving rocker arm A3 of the differential motion gear T3 is coupledwith the bidirectional input power source.

The sun gear set T1 and ring gear set T2 are coupled with the outputshaft S1 via one-way driving mechanisms SC231 and SC221 respectfully.The one-way driving mechanisms SC232 and SC222 are installed between thesun gear T1 and ring gear T2, and the fixed case. The acting directionwill be reverse to the one-way driving mechanisms SC231 and CS221 to becoupled with the output shaft.

In the output on the first rotating direction, the sun gear T1 is madestationary by the one-way driving mechanism SC232 installed between thesun gear and the fixed case. The output shaft S1 is driven by theone-way driving mechanism SC221 installed between the output shaft S1and the ring gear T2. The output ratio will be:

    R=1/(1+T2/T1)

When the input shaft SO is driven in an opposite direction, the ringgear T2 is held stationary by the one-way driving mechanism SC222installed between the ring gear T2 and the fixed case. The output shaftS1 is driven by the one-way driving mechanism SC231 installed betweenthe sun gear T1 and the output shaft S1. The output ratio will be:

    R=1/(1+T1/T2)

FIG. 4 shows an example of an application wherein the ring gear iscombined with the output shaft. The main structural relationship will beas follows.

The driving arm A3 of the differential motion gear T3 is coupled withthe case via the one-way driving mechanism SC422.

The input shaft SO combines with and drives the sun gear T1 to provide arotary motive force input, and is coupled with the ring gear T2 and theoutput shaft S1 via the one-way driving mechanism SC421.

The sun gear T1 is engaged with the differential motion gear T3 andcombined with the input shaft SO.

In the output on the first rotating direction, the ring gear T2 and theoutput shaft S1 are driven by the one way driving mechanism SC421installed between the output shaft S1 and the input shaft SO. Theone-way driving mechanism SC422 installed between the rocker arm A3 ofthe differential motion gear T3 will idle, and the output ratio in thisstate will be:

    R=1

When the input shaft SO rotates in an opposite direction, the one-waydriving mechanism SC421 between the ring gear T2 and the input shaft SOwill be idle. The one-way driving mechanism SC422 installed between thearm A3 of the differential motion gear T3 and the case will be lockedup. The differential motion gear T3 will be in the output state by thering gear T2. The output ratio at this state will be:

    R=-T1/T2

The present invention provides further for an innovative quick-returndifferential motion gear system to switch the driving direction of thedriving side and change the output speed ratio as well as the rotatingdirection simultaneously so that the driving axis will rotate forwardlyand reversely in unequal speed ratios to improve the convenience andquick-return motion efficiency of the mechanism.

The embodiment of the quick-return differential motion gear system isdivided into (A) series type; (B) parallel type; and (C) double-actingtype based on the distribution of the one-way driving mechanism of thestructural components. It is explained based on the embodiment asfollows:

(A) Series type:

FIG. 5 shows the schematic drawing of the embodiment of a series typequick-return differential motion gear system to control the speed ratioby changing the input direction. It is constituted chiefly as follows:

The shaft S50 is coupled with a reversible input rotating power toprovide the quick-return differential motion gear system with a sourceof reversible driving force.

The sun gear T51 to be supplied with the rotating force is coupled withthe input shaft S50 via a one-way driving mechanism SC51 and is engagedwith the differential motion gear set T52.

The driven arm A52 is coupled with the output shaft S51 via the drivingmechanism SC52 and is engaged with the ring gear T53.

The ring gear T53 is in the shape of an inner, circular gear is engagedwith the differential motion gear T52 and coupled with the fixed case.

The one-way driving mechanism SC53 is installed between the input shaftS50 and the output shaft S51.

The relationship of input-direction conveying a motive force of theabove-one way driving mechanism SC53 will convey a motive force in onedirection, while SC51 and SC52 will provide the motive force on drivingreversely.

Other structural components of the gear box relating to the case,screws, etc., are not described otherwise herein.

(B) Parallel type:

The parallel type quick-return gear system to control speed ratio bychanging the input direction is shown in the schematic drawing in FIG.6. The main structure includes:

The input shaft is coupled with the quick-return differential motiongear system to input forward and reverse rotating forces.

The sun gear T61 is connected to the input shaft S60 and coupled to thedifferential motion gear T62.

The differential motion gear T62 is coupled with the sun gear T61 andthe ring gear T63, and is fixed on the case;

the ring gear T63 is coupled with the differential motion gear T62 anddrives the output shaft S61 by means of the conveying of motive force ofthe one-way driving mechanism SC622. It is coupled with the case bymeans of another one-way driving mechanism SC621 to rotate or remainstationary in different thrust directions.

The one-way driving mechanism SC623 is installed between the input shaftS60 and output shaft S61.

The relationship of the acting-direction of the above one-way drivingmechanism SC623 to convey motive force is that in a first drivingdirection, SC621 allows the ring gear T63 to rotate freely, SC622 causesthe output shaft S61 to rotate, and SC623 allows idle rotation betweenthe input shaft S60 and the output shaft S61. In the second drivingdirection, SC621 causes the ring gear T63 to be stationary, SC623 causesthe input shaft S60 to be connected with the output shaft S61, and SC622allows idle rotation between the output shaft S61 and the ring gear T63.

Other related structural components of the accustomed gear box of thecase, screw, etc., are not described herein otherwise.

(C) Double-acting type:

The embodiment of the double-acting type quick-return differentialmotion gear system to control the speed ratio by changing the inputdirection is shown in the schematic drawing in FIG. 7 and is constitutedchiefly by:

The input shaft S70 is coupled with the quick-return differential motiongear system for the input of opposite rotary motive forces and coupledwith the output shaft S71 via the one-way driving mechanism SC722.

The sun gear T71 is connected to the input shaft S70 and coupled withthe differential motion gear T72.

The differential motion gear 72 is coupled with the sun gear T71 and thering gear T73. The spindles of the various differential motions gearsare installed on the driving arm jointly to drive the output shaft S71,which is also coupled to the input shaft S70 via the one-way drivingmechanism SC722.

Ring gear T73 is coupled with the differential motion gear T72 and thencoupled with the fixed case via the one-way driving mechanism SC721 torotate or remain stationary in different directions.

The one-way driving mechanism SC722 is installed between the input shaftS70 and the output shaft S71.

The relationship of the acting-direction to convey motive force of theabove one-way driving mechanism is that SC721 allows the ring gear T73to rotate freely in a first driving direction, while SC722 causes theconveying of motive force between the input shaft S70 and the outputshaft S71. SC721 causes the external gear to be stationary in the seconddriving direction. SC722 allows the input shaft S70 and the output shaft571 to rotate idly. By this time the output shaft S71 is driven by thedifferential motion gear T72 and the driving arm to perform a reductionoutput.

Other related structural components of the gear box, and screws are notdescribed herein otherwise.

The differential motion gear system to control speed ratio by changingthe input direction can be combined further with an automatic loadsensor to control the opposite rotating of the driving source of thedriving axle to change the output speed ratio.

Excepting artificial switching of the rotating direction of the sourceof the rotating motive force, it allows to detect further the loadcurrent of the source of the motive force for reference of the time tochange the direction. It is generally used to detect the load current ofthe motor to change the direction of the rotation of the motor. When theload current exceeds the setting conditions, the differential motiongear system will control the speed ratio by changing the input directionfrom one direction into an opposite direction. It may change from asmaller speed ratio, or further entail simultaneous conversion of theoutput direction. In addition, the detecting method also may use amechanical torsion sensor as the basis of control and detecting. If thedriving side has the load of other motive forces, such as an engine, thedirection converting mechanism may be driven on overloading by combiningit with a torsion sensor or a restricting device to change the rotatingdirection of the input of the differential motion gear system.

In practical applications, the following options are available:

To combine a conventional reciprocal mechanism on the input or outputend will be able to obtain the variable output with bidirectionalinvariable speed ratio.

In summary, the innovative differential motion gear system to controlthe speed ratio by changing the input direction shows the output in sameoutput direction with different speed ratios, or the output in adifferent direction with different speed ratio to be produced by theopposite driving of a differential motion gear system at the side ofdriving force. It may be applied for various driving with the one kindof the structure of multiple sets of series stages or the mixed stages.

I claim:
 1. I claim a differential motion gear system to control a speedratio by changing the input direction comprising:a) an input shaftrotatable in opposite directions; b) an output shaft; c) a first one waydrive mechanism connected between the input shaft and the output shaft;d) a sun gear connected to the input shaft; e) a differential motiongear engaged with the sun gear; f) a ring gear engaged with thedifferential motion gear; g) a stationary case; and, h) means attachingthe ring gear to the stationary case so as to prevent relative rotationbetween the ring gear and the stationary case, wherein the meansattaching the ring gear to the stationary case fixedly attaches the ringgear to the stationary case so as to prevent any relative rotation ofthe ring gear relative to the stationary case.
 2. The differentialmotion gear system of claim 1 further comprising;a) a second one waydrive mechanism connected between the sun gear and the input shaft; and,b) a third one way drive mechanism connected between the differentialmotion gear and the output shaft.
 3. I claim a differential motion gearsystem to control a speed ratio by changing the input directioncomprising:a) an input shaft rotatable in opposite directions; b) anoutput shaft; c) a first one way drive mechanism connected between theinput shaft and the output shaft; d) a sun gear connected to the inputshaft; e) a differential motion gear engaged with the sun gear; f) aring gear engaged with the differential motion gear; g) a stationarycase; h) means attaching the ring gear to the stationary case comprisinga second one way drive mechanism connected between the ring gear and thestationary case; and i) a third one way drive mechanism connectedbetween the ring gear and the output shaft.
 4. The differential motiongear system of claim 3 further comprising connecting means to fixedlyconnect the differential motion gear to the stationary case.
 5. Thedifferential motion gear system of claim 3 further comprising connectingmeans to fixedly connect the differential motion gear to the outputshaft.